As mobile multi-media functionality grows rapidly, portable electronic devices are becoming a more integral part of peoples' daily lives. As such, mobile devices are increasingly required to provide high display performance in a variety of ambient light conditions and applications without sacrificing battery life. Additionally, as portable devices progressively include more features and become more complex, battery power increasingly becomes a limiting factor in the performance of such devices. Conventional displays for portable devices require that a user make trade offs between power consumption and display performance, and provide little control over display settings and power usage.
Recently, displays have been developed which can operate in multiple modes and harness ambient light to improve display performance. For example, such modes may include a transmissive mode, where light from a back light is modulated, a reflective mode where ambient light is modulated, and a transflective mode where both light from a backlight and a relatively large amount of ambient light are modulated to create an image. For example, U.S. Patent Application Publication No. 2010/0020054 to Jepsen describes an LCD display having pixels that include separate transmissive and reflective portions. As a result, the effective aperture ratio of the display in a transmissive mode is reduced in comparison to displays in which the whole pixel is transmissive. The LCD display of the Jepsen publication also separately controls both portions. The separate control functionality requires separate data interconnects and additional drivers to control each portion independently, which substantially adds to the complexity of the backplane design and further reduces the space on the chip for light transmission.
A need exists for portable device displays that can transition between transmissive, reflective and/or a range of transflective operating modes using the same data interconnects to control both reflective and transmissive outputs of a display. In addition, a need exists for a device which provides transmissive, reflective and/or a range of transflective operating modes without sacrificing the effective aperture ratio of the display.